Why do large lead sculptures need internal support?

Large lead sculptures require internal support because lead is a very soft and malleable metal. Due to these physical properties, the material is susceptible to creep—a slow, permanent deformation that occurs under prolonged stress.123

If a large or life-size lead sculpture is left unsupported, the weight of the metal itself causes the structure to sag or collapse over time. To prevent this distortion, artists must incorporate an internal framework, or armature, typically constructed from more rigid materials such as iron rods or pipes, to provide the necessary structural integrity.145